Department of Anatomy, College of Medicine, University of Lagos, Idi-Araba, Lagos, Nigeria.
Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, Yale University, New Haven, Connecticut, USA.
Sci Rep. 2023 Apr 26;13(1):6819. doi: 10.1038/s41598-023-33648-4.
There are conflicting reports on trends of semen parameters from different parts of the globe. However, in recent times there is dearth of information on the trend in Sub-Saharan countries. Therefore, in this study we aimed at determining the trends in semen parameters in Nigeria and South Africa between 2010 and 2019. A retrospective study of semen analyses of 17,292 men attending fertility hospitals in Nigeria and South Africa in 2010, 2015 and 2019. Patients who had undergone vasectomy and those who had a pH less than 5 or greater than 10 were excluded from this study. The following variables were assessed: ejaculate volume, sperm concentration, progressive motility, total progressively motile sperm count (TPMSC), total sperm count, and normal sperm morphology. Between 2010 and 2019, significant trends of decreasing values were observed in normal sperm morphology (- 50%), and the ejaculatory volume (- 7.4%), indicating a progressive deterioration of the values in both countries. In Nigeria, there were significant decreases in progressive motility (- 87%), TPMSC (- 78%), and sperm morphology (- 55%) between 2010 and 2019 (P < 0.001). Spearman`s rank correlation revealed significant negative associations between age and morphology (ρ = - 0.24, P < 0.001), progressive motility (ρ = - 0.31. P < 0.001), and TPMSC (ρ = - 0.32, P < 0.001). Patients in South Africa were younger than those from Nigeria, with also a significantly higher sperm morphology, sperm concentration, progressive motility, total sperm count and TPMSC. Our findings provide a quantitative evidence of an alarming decreasing trend in semen parameters in Nigeria and South Africa from 2010 to 2019. It also proves that astheno- and teratozoospermia are the leading causes of male infertility in these regions. In addition to this, it also shows empirically that semen parameters decrease with advancement in age. These findings are the first report of temporal trends in semen parameters in Sub-Saharan countries, necessitating a thorough investigation on the underlying factors promoting this worrisome decline.
关于不同地区精液参数的趋势存在相互矛盾的报告。然而，最近有关撒哈拉以南国家趋势的信息却很少。因此，在这项研究中，我们旨在确定 2010 年至 2019 年期间尼日利亚和南非精液参数的趋势。这是一项对 2010 年、2015 年和 2019 年在尼日利亚和南非生育医院就诊的 17292 名男性精液分析的回顾性研究。排除了接受输精管切除术和 pH 值小于 5 或大于 10 的患者。评估了以下变量：精液量、精子浓度、前向运动精子比例、总前向运动精子数（TPMSC）、总精子数和正常精子形态。2010 年至 2019 年间，正常精子形态（-50%）和射精量（-7.4%）呈显著下降趋势，表明两国的数值都在逐渐恶化。在尼日利亚，2010 年至 2019 年间，前向运动精子比例（-87%）、TPMSC（-78%）和精子形态（-55%）显著下降（P<0.001）。Spearman 秩相关分析显示，年龄与形态（ρ=-0.24，P<0.001）、前向运动精子比例（ρ=-0.31，P<0.001）和 TPMSC（ρ=-0.32，P<0.001）之间存在显著负相关。南非患者比尼日利亚患者年轻，精子形态、精子浓度、前向运动精子比例、总精子数和 TPMSC也明显更高。我们的研究结果提供了定量证据，表明 2010 年至 2019 年期间尼日利亚和南非的精液参数呈明显下降趋势。这也证明了弱精症和畸形精症是这些地区男性不育的主要原因。此外，它还从经验上表明，精液参数随年龄的增长而下降。这些发现是撒哈拉以南国家精液参数时间趋势的首次报告，需要对促进这种令人担忧的下降的潜在因素进行彻底调查。
